Black Max Boiler Handhole & Manhole Gaskets

Additional Information

Compared to spiral wound gaskets, Black-Max® seals better with our Exfoliated Graphite and has much better recovery properties. It also weighs less than half of that of spiral gaskets, so they are easier to handle and you will save on freight charges. And while spiral gaskets require near-perfect conditions, Black-Max® gaskets seal on rough, pitted surfaces under less compressive load.

Zero Leakage Under Pressure - Tests by major boiler manufacturers confirm that Black-Max® gaskets seal- with zero leakage-on steam to 450 psi and on cold-water hydro tests up to 1500 psi and Black-Max® withstands working temperatures up to 500 deg Fahrenheit. Rubber gaskets can't withstand that kind of pressure and heat.


Black-Max® withstands working steam temperatures up to 1,200°F. Rubber gaskets can’t withstand that kind of pressure and heat. Easy Removal and requires no scraping, chiseling or grinding - resulting in lower maintenance costs and less downtime.

Clearly Marked Sizes. Each gasket’s size is permanently marked, so you’ll know immediately that you have the one you need. Maximum Sealing on Rough Surfaces. The proprietary graphite used to manufacture Black-Max® is chemically inert (pH 0 -14) and resistant to chemicals used in treating boiler water.